More than that exists. There have been several Crossroads DVDs released over the years which included episodes from the 60s and 70s also. However, sequences of episodes from the 60s and 70s are incomplete so when they were repeated on UKGold about 20 years ago, they began with episodes from the 1980s.

Around 5000 episodes of Crossroads were made (I don't include the reboot series) of which about 1700 still exist.